Skip-hoist structure



Patented Apr. 9, 1929.

liFlCE..

VANI.

SKIP-TLIOIST STRUCTURE.

Application filed May 4,

ln skip hoists there is a cable operating,` :troni the top and to it is attached a bucket bail guided by upright and inclined tracks. Here totorc. so tar as l. know. the adjacent ends oi the upright and inclined tracks have been connected by curved tracks ot long1 radius. The maximum rope pull. and track reaction occurred at these curved tracks and a construction including; these curved tracks was didicult to ogure and to lay out and to construct and the curved tracks were diilicult to hold in place. f rthe principal object et the present invention is. to lessen the track reactions and rope pulls and to provide a construction simpler to detail and easier to hold necordingv to the present invention the in clincd and uprighttracks are connected by tanagent tracks, that is, straight short cut tracks which operate to lessen the maximum loads to which reference has been made and which occur where the ends of the upright and inclined tracks are connected. by means ot curved tracks ot long' radius according` to practice heretofore followed.

rlhe invention also comprises the improvements to be presently described and finally claimed.

ln the 'following description reference will be made to the accompanying drawing :torminp; part hereoll and in which lligure l is an elevational view illustrating the lower inclined. tracks connected with the vertical tracks in accordance with the present invention and by means et tangent tracks, and

l!" 2 is a similar view illustrating' the appliraion ot the present invention to the upper part ot a skip hoist run.

ln the drawing l generally indicates the vertical tracks, 2 generally indicates the inclined tracks' at the bottom of the structure, and 3 the inclined tracks at the top ot the structure. 4 is a cable or rope operating from the top ot the structure and it is shown as lguided by sheaves 5 carried bythe framework or structure 6 oit the tower. The bail 7 oli the bucket 8, or more accurately7 the guide wheel 9 ot the bail runs between the tracks and is Serial N0. 275,05?.

guided by them, and to the bail is attached the cable Ll. l0 generally indicates the tangent tracks or straight short cut tracks by which the vertical tracks l are connected with the inclined tracks 2 and 3.

ln use the tangent tracks l0 approach vertical direction at once and thereby reduce the track thrust to a minimum which lcssens the rope pull and maximum effort ol the driving machinery. Another way ot explaining the operation et the described tangent tracks is to compare their operation and results with the operation and results of curved tracks such have been heretofore employed. Vllhen any tracks are parallel with the rope pull the best conditions obtain, and it the tracks were at right angles to the rope pull the worst conditions would. obtain. ln the second case the angle corresponding to the angle a, Fig. l, is 180, and inthe first case it 90o, consequently the smaller the angle a the better are the conditions tor limiting the maximum rope pull and. track thrust. Referring to l. represents the rope pull, c the track thrash and d the bail pull, and in that particular case the angle L is 70 and the angle e between c and the horizontal is 19 1l. Assuming; that the dead weight ot' the bucket equals 100% the rope pull b equals 80%, and the track thrust c equals 54%. All other things remainiita` the same. it the inclined tracks 2 and the upright or vertical tracks l were connect ed by a curved track of long: radius. the angle corresponding' with a would equal 60, the anfgle correspon dino; with e would equal 32, the rope pull would equal 90%, and the track thrust would equal The bail pull in each case is 80%. .i

lt may be remarked that the sharp bends where the tangent tracks yioin the inclined and vertical tracks are in the direction of stress on the wheel 9 and therefore are unohjectionable. ln connection with the comparison between the taiurent and curved connecting' tracks.. it may be said that the conditions recited refer more particularly to the entrance portion of the curved tracks and ot course as the latter approach the vertical the pull and thrust `diminish but the maximum pull and thrust lWith the curved tracks exceed the maximum pull and thrust with the tangent tracks, and it is the maximum pull and thrust that have to be taken care of.

It will be obvious to those skilled in the art to which the invention relates that m0difications may be made in details of construction and arrangement and in matters of mere form without departing from the spirit of the invention which is not limited to such matters or otherwise than the prior art and thc appended claim may require.

I claim:

In a skip hoist having a cable operating 15 from the top and the bucket bail attached to the cable and including relatively inclined tracks for guiding the bail, means for connecting the inclined travis which com rise tangent tracks, substantially as dcscri ed.

ROBERT H. BEAUMONT. 

